A Hidden Words puzzle aimed at 16- to 19- year olds, containing mathematical words that they should know

Instructions below

There are 32 hidden words in this grid. They are all mathematical words that you should know for AS Level (UK) or before. They appear horizontally - left or right, vertically - up or down, and diagonally - forwards or backwards. All words have four or more letters.
When you notice a word, left-click on the first letter of the word, drag the mouse to the end of the word, and then release the mouse button.

If you were right, the letters on the grid will change colour, and the word will appear on the right of the screen.
When you have all 32 words, the letters that haven't been used will spell out the name of a famous French amateur mathematician, 1601-1665.
Keep going until you've found all 32 words. Have fun!